Wondering what could be wrong with your water heater because it’s not heating water? Day & Night Plumbing, Heating & Cooling has you covered with the most common reasons your water heater stopped working.

Water heaters are one of your home’s most labor-intensive appliances. You rely on your water heater daily to heat water for showers, baths, dishwashing, and laundry, and it is designed to withstand that daily abuse. But when your water heater breaks down, something isn’t right.

Take Safety Precautions When Troubleshooting Your Water Heater

Before you open your home’s water heater and check it out, please read the next section. Water heaters can be dangerous to work on. Electric water heaters handle high-voltage electricity, while gas water heaters handle combustion. Both can kill you if you’re not careful–they’re just dangerous in different ways.

Only attempt water heater troubleshooting if you feel comfortable working with electricity, gas, water, and exhaust.

Important Safety Tips When Troubleshooting Your Water Heater

• Turn off the gas valve supplying the water heater.
• Turn off the circuit breaker supplying power to the water heater.
• Turn off the water valve supplying the water heater. (You may want to do this one last.)
• Have the proper electrical testing equipment ready. For example, use a multimeter, a device that measures voltage, current, and resistance.
• Have the proper tools ready.

Don’t burn yourself or get scalded on hot metal/hot water while working on your water heater. Now…

Here Are 10 Reasons Why Your Water Heater Will Stop Working

#1 You Have No Power or Fuel

When troubleshooting any mechanical appliance, it’s always best to start with the obvious. Make sure your water heater has power and/or fuel.

Electric water heaters: Ensure the unit is plugged in and check your circuit breaker panel to ensure your water heater’s circuit breaker has not tripped.

Gas water heaters: Ensure the gas valve is fully open and functioning properly. Also, ensure gas is reaching the appliance.

#2 Faulty Thermostat

The thermostat controls water temperature. If it fails, your heater won’t heat water properly.

To test your water heater’s thermostat:

• Turn off the power to your water heater.
• Remove the thermostat.
• Grab your multimeter (a tool for measuring electrical properties) and test your thermostat for continuity (to check whether electricity can flow through it).

If there is no continuity, your thermostat will need to be replaced.

#3 Bad Heating Element

Electric water heaters rely on heating elements. If the element fails, you’ll have no hot water.

To test an electric heating element:

• Turn off the power to the water heater.
• Remove the two power wires connecting to the heating element.
• Grab your multimeter, a tool used to measure electrical resistance, voltage, and current, and test your heating element.

Set your multimeter to the ohms (Ω) setting. If the reading is above 12–13 ohms (Ω), the heating element will need to be replaced.

#4 Pilot Light Went Out

Ah, yes…the good ol’ pilot light that needed daily attention. While we still see water heaters with a pilot light out there, most water heaters today have an electronic module that controls the pilot light. When the pilot light goes out on a traditional water heater, it won’t produce hot water.

Pilot lights are easy to relight if you know how.

Simply look at your water heater instruction manual OR

Look at the water heater operations sticker located on the tank. (This sticker is located where everyone can easily read it in case your water heater needs servicing.)

Give Day & Night Plumbing, Heating & Cooling a call if you smell gas or cannot relight your pilot for any reason.

#5 Broken Drain-down Valve

The drain valve at the base of your tank lets you drain or flush sediment. If it breaks, your tank can be ruined.

The drain-down valve can become so clogged with sediment that it won’t release any water from your tank…

Or the drain valve will go completely bad and start to leak water into your water heater’s burner compartment. (If this happens, it will look like your water heater tank is leaking from the bottom.)

Once you have a leak coming from your water heater’s drain valve, it’s time to drain that water heater down and replace the valve.

#6 Problem with Expansion Tank

Expansion tanks cushion against pressure changes as your water heater heats up or cools down.

Wisconsin state law does not require an expansion tank to be installed on a water heater. However, many water heater manufacturers suggest installing an expansion tank.

Water heater expansion tanks are designed to absorb any excess pressure caused by thermal expansion (the increase in water volume as it heats up) inside your water heater tank. If your water heater does not have an expansion tank, you will more than likely experience leaking pressure relief valves (safety devices that release excess pressure), water hammering (loud banging noises in pipes), and water heater tank leaks.

If you’re interested in troubleshooting your expansion tank, follow these steps.

• Turn off the water supply to the water heater.
• Turn off the gas or electricity to the unit.
• Relieve any existing pressure from the plumbing system.
• Check the air charge on the expansion tank.

The air pressure in the tank ought to match the home’s current water pressure. If the psi inside the tank differs by 1 or 2 pounds, the expansion tank will need to be replaced.

Lastly, if you see any visible cracks or leaks on the tank, it will need to be replaced.

#7 Your Water Heater is Overheating

Leaving water on the stove too long will burn it, and the same happens with your water heater. If your water heater overheats, it will either shut off or vent through the pressure relief valve at the top of the water heater tank.

Electric water heaters have a high-limit safety feature that shuts off power if the unit overheats. You can reset it. These high limits are common on both water heaters and electric furnaces.

Resetting Your Electric Water Heater High Temperature Lockout

• Turn off the power to the water heater.
• Remove the access panel to the thermostat and heating element.
• Locate the red reset button on your electric water heater thermostat.
• Push and hold the button for three seconds.
• If you hear a click, then you can bet it was tripped at some point.
• Replace the access panel. Turn the power back on to the water heater.
• Wait 30 minutes to an hour for water to begin heating. If it heats water properly, problem solved!

If your high limit continues to trip, there is a deeper problem that will require professional inspection.

#8 Damaged Water Heater Tank

This one really should tell itself. If water is leaking from the bottom of your water heater, it has stopped working for that reason alone.

Over time, every water heater reaches the end of its life. Normal wear and tear will eventually cause your water heater to stop working. Most units begin to show issues after about 6 years of use.

All water heaters eventually wear out. Most last about six years before problems start.

The best way to avoid getting stuck with an old water heater is to keep up with annual water heater maintenance. Water heater maintenance not only keeps your water heater running efficiently but also finds minor problems before they become major ones. Sign up for our maintenance club to help get every dime out of your old water heater!

That being said, water heaters have been known to last and keep working for 10 years.

#10 Damage

The last thing we have for you when troubleshooting why your water heater stopped working is damage. Now, when most people hear the word ‘damage,’ they think someone dropped their water heater into their kitchen sink. What we mean by ‘damage’ is any damage that may have occurred after installation.

Water heaters can be damaged in many ways. Flood damage, busted pipes, sewer damage, rodents chowing down on wiring, and even natural disasters can cause damage to your water heater.

One of the most common causes of water heater damage is high water pressure. Any water pressure that exceeds 80 PSI is too high for your water heater. High water pressure will shorten your water heater’s lifespan.

Last Words and Fixes

Alright, friends, if you have a damaged water heater due to any of the above reasons, give Day & Night Plumbing, Heating, and Cooling a call immediately! We service all types of water heater damage and will give you a fair and affordable price to match.